<?php 
class MY_Cart extends CI_Cart
{
    function total()
    {
        $b=$this->_cart_contents['cart_total'];
        $tong = 0;
        $data['cart']=$this->contents();
        foreach($data['cart'] as $car)
        {
            $a=$car['product_shipping'];
            $tong =$tong + $a ;
        }
    return $b + $tong;
    }
    function total_shipping()
    {
        $tong = 0;
        $data['cart']=$this->contents();
        foreach($data['cart'] as $car)
        {
            $a=$car['product_shipping'];
            $tong =$tong + $a ;
        }
        return $tong;
    }
}